A battery bridge is understood to mean the contact of an electric circuit of an electronic device that remains open last. If the open contact of the battery bridge is closed following assembly and testing of the electronic device, the device is thus activated, i.e., the electric circuit forming the basis of the device is permanently closed.
With regard to an electronic implant, correct activation is of course of particular importance, since lasting fault-free functioning of the implant must be ensured. By way of example, cardiac pacemakers, cardioverter defibrillators, electronic drug delivery devices, or implantable sensors (biomonitors) are currently used as electronic implants.
Due to the requirement that an electric circuit for electronic devices of this type should take up as little space as possible, said circuit is currently often produced by means of SMT (surface mounting technology). In the case of surface mounting technology, components are soldered directly onto a printed circuit board by means of solderable connection faces.
In order to activate an electronic device, a soldering method was used previously, for example, in which tin is applied by means of a soldering iron and closes the circuit between two adjacent soldering faces on the printed circuit board (PC board or PCB). The disadvantage of this conventional solution lies in the fact that soldering methods nowadays cannot be reliably automated in respect of the small structures as can be provided on highly compact circuits, since the soldering process is influenced by the solder amount, the soldering temperature, the fluxing agent, the cleanliness of the surfaces, and the like.
It is also known to keep a contact of the battery strip insulated by means of a temporary insulator until activation. Once the electronic device is finished, the contacts having been welded, the device is powered up via test points. Following successful power-up, the temporary insulator is manually removed; the battery strip, which has not yet been welded on, is manually held down and manually welded on by means of one to two weld points. This method has the disadvantage that the circuit must be activated by a complex power-up device, wherein a connection lug of the battery always has to be insulated via a temporary insulator. An accidental contacting of the strip (bounce of the contact) and therefore accidental initialization should be avoided as a result of this measure. It is also disadvantageous that in this method, following successful initialization of the circuit, the temporary insulator is manually removed from the battery connection strip, the strip is placed by means of tweezers on the circuit, and then must be welded on to the weld path. This complex manual process step is time-consuming and requires fine motor skills. It cannot be automated from the viewpoint of cost-effectiveness. In addition, additional material has to be provided, fed and positioned for the temporary insulator. The same is true for the connection strip.
An alternative solution lies in closing the circuit by means of a bonding method. For this purpose, material (for example, aluminum strip/wire) has to be fed, and the strip ends have to be welded on by means of friction welding or laser welding. The bonding method presupposes an already fixed internal structure of the electric circuit, for example, by gluing, on account of the high forces that occur as the strip is held down and welded on (resistance welding). However, this is problematic for electronic implants, since no adhesives can be used, so as to avoid a high expenditure of time for the curing of an adhesive and also adhesive evaporation, which can have a negative effect on the electronic behavior of the device.
A further alternative possible embodiment for a battery bridge could consist in closing the circuit by means of a plug-in contact. However, for electronic implants there is the requirement that the electronic circuit must operate reliably over the entire service life of the implant, that is to say up to 10 years. The material fatigue of the springs or contact resistances, which change over time, however, constitute a risk in respect of the product reliability. The use of plug-in contacts/spring contacts for electronic devices such as electronic implants therefore is not recommended.
The present invention is directed toward overcoming one or more of the above-mentioned problems.